Method and apparatus for coordinating resources

ABSTRACT

Embodiments of the present disclosure provide a method in a base station for coordinating resources in a wireless communications system with carrier aggregation in which a first group of terminal devices is served by a primary cell and one or more secondary cells under control of the base station. The method comprises obtaining information indicating arrival of a second group of terminal devices at coverage of the base station. A speed of any terminal device of the second group is higher than a speed of any terminal device of the first group. The method also comprises releasing resources on at least one secondary cell of the one or more secondary cells and allocating the released resources to the second group of terminal devices.

PRIORITY

This application is a continuation under 35 U.S.C. § 120 of U.S.application Ser. No. 15/503,975 which is a U.S. National Stage Filingunder 35 U.S.C. § 371 of International Patent Application Serial No.PCT/CN2014/084838 filed Aug. 20, 2014 and entitled “Method and Apparatusfor Coordinating Resources.”

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to communicationsfield, and more particularly to a method, apparatus, base station, andcomputer program for coordinating resources in a wireless communicationssystem with carrier aggregation.

BACKGROUND

This section introduces aspects that may facilitate a betterunderstanding of the present disclosure. Accordingly, the statements ofthis section are to be read in this light and are not to be understoodas admissions about what is in the prior art or what is not in the priorart.

The concept of carrier aggregation (CA) was introduced in ThirdGeneration Partnership Project (3GPP) Long Term Evolution (LTE) release10 and now has been widely adopted by global operators.

Carrier aggregation refers to transmitting data on multiple carriersthat are contiguously or separately located in a spectrum. In carrieraggregation, each aggregated carrier is referred to as a componentcarrier (CC). The component carrier may have a bandwidth of 1.4, 3, 5,10, 15 or 20 MHz and a maximum of five component carriers may beaggregated, hence the maximum aggregated bandwidth may be 100 MHz.

A user equipment (UE) supporting carrier aggregation may be configuredby a base station, e.g. an evolved Node B (eNodeB or eNB) in an LTEnetwork, with a primary component carrier (PCC) and one or moresecondary component carriers (SCCs). There is no definition of whichcarrier should be used as the PCC. The configuration of the PCC is UEspecific and will be determined according to loads on various carriersas well as other relevant parameters. Therefore, different UEs may usedifferent sets of component carriers with different component carriersbeing configured as the PCCs.

When carrier aggregation is used, there are a number of serving cells,one for each component carrier. The Radio Resource Control (RRC)connection is only handled by a primary serving cell (PCell) served bythe PCC. The secondary component carriers serve secondary serving cells(SCells). The SCells may be configured/de-configured, added, removed ormodified for the UE via RRC signaling, e.g.RRCConnoctionReconfiguration, while the PCell is only changed with ahandover procedure. In LTE technology, the terms “PCC” and “PCell” areusually used interchangeably and the terms “SCC” and “SCell” are alsoused interchangeably.

When a UE is configured with SCells, the configured SCells need to beactivated before they can be scheduled for data transmission. The SCellsmay be activated/deactivated by a base station via Media Access Control(MAC) layer commands, while the PCell configured to the UE is alwaysactivated. The base station may activate and deactivate the SCell(s) bysending an Activation/Deactivation MAC control element as described insection 5.13 of 3GPP Technical Specification (TS) 36.321, V11.5.0. Uponsuccessful reception of the activation command, the UE may be ready toreceive assignments on the SCells with a certain time, e.g. 8 ms afterthe activation command was transmitted over the air. So the activationand de-activation procedure may be very fast and controlled totally bythe base station.

With the emergence of advanced transport vehicles, especially thedevelopment of high-speed trains, it becomes more challenging to providereliable services for UEs in high-speed movement with efficientutilization of valuable frequency resources.

Taking a high speed train scenario as an example, it has some uniquecharacteristics. For example, the UEs on a high speed train (which willbe referred to as HST UEs) move as one group with a high speed, andpenetration loss to the train is very high, and thus path loss from thebase station to the HST UEs is also high. Normally, if conventionalcells along the rail track are re-used to provide coverage for the HSTUEs, it is very hard to optimize the coverage and resource/interferencemanagement for both the HST UEs and non-HST UEs, which may located closeto the rail track but are static or moving more slowly than the HST UEs.

Besides, most operators allocate a higher frequency spectrum for LTEcompared with Global System for Mobile Communication (GSM). Therefore,the coverage problem becomes more serious since the path loss andpenetration loss are much higher at higher frequency points than lowerfrequency points.

There are two main solutions for providing coverage for HST UEs, asillustrated in FIG. 1, where each base station is configured with twocarriers f1 and f2. FIG. 1 (a) illustrates a first solution that may becalled a “common” solution, where carriers f1 and f2 are common for FISTand non-HST UEs. It also means that when a HST is passing a cell, thenon-HST UEs and HST UEs in the cell are sharing the radio resources oncarriers f1 and f2, and the base station won't treat them differentlywith regard to scheduling and/or radio resource management (RRM).

FIG. 1(b) illustrates a second solution that may be called a “dedicated”solution, where carrier f1 is always used for non-HST UEs while carrierf2 is reserved for HST UEs only, no matter whether the HST UEs arepresent or not.

The common solution as illustrated in FIG. 1(a) cannot achieve good loadmanagement as HST UEs are group handed over from a cell to another in aquick speed. The instantaneous load may be very high when taking non-HSTUEs into account and therefore UE experience may be deteriorated. Inaddition, the HST UEs may be subjected to interference fromtransmissions of neighboring non-HST UEs as both carriers f1 and f2 aresimultaneously used by the non-HST UEs. This interference may be veryserious mainly because the HST UEs experience much more path loss and noefficient intra-frequency interference handling mechanism is applied.Therefore, the quality of service (QoS) for the HST UEs may not beguaranteed.

The dedicated solution as illustrated in FIG. 1(b) may provide a goodQoS to HST UEs without any interference from transmissions ofneighboring non-HST UEs because of dedicate use of carrier f2. However,this good QoS is achieved at the cost of low spectrum utilization sincethe HST service in a cell is limited to a very short time period onlywhen the HST is passing the cell. Therefore, the spectrum cannot beflexibly and efficiently utilized, which causes this solution costly.

In the “dedicated” solution, such a dedicated carrier may be based on asame site/antenna or different sites/antennas, where the latter casewill have separate antennas and possibly sites. The dedicated solutionwith separate sites/antennas may provide optimized and flexible HSTcoverage more accurately, but this may also increase infrastructureinvestment and network management/optimization cost, like Physical layerCell Identity (PCI) handling, and antenna tilting. Sometimes, if apaging channel (PCH) is not optimized between HST cells and non-HSTcells, it may cause interference and degrade network performance due toa common reference signal (CRS) collision.

Therefore, the existing solutions are very hard to balance betweenQoS/interference management and spectrum/cost-efficient HST coverage.

SUMMARY

Various embodiments of the disclosure aim at addressing at least part ofthe above problems and disadvantages. Other features and advantages ofembodiments of the disclosure will also be understood from the followingdescription of specific embodiments when read in conjunction with theaccompanying drawings, which illustrate, by way of example, theprinciples of embodiments of the disclosure.

In a first aspect of the present disclosure, a method in a base stationfor coordinating resources in a wireless communications system withcarrier aggregation is proposed. In the wireless communications system,a first group of terminal devices is served by a primary cell and one ormore secondary cells under control of the base station. The methodcomprises obtaining information indicating arrival of a second group ofterminal devices at coverage of the base station. A speed of anyterminal device of the second group is higher than a speed of anyterminal device of the first group. The method also comprises releasingresources on at least one secondary cell of the one or more secondarycells and then allocating the released resources to the second group ofterminal devices.

In some embodiments, the method may further comprise informing one ormore neighboring base stations of the arrival of the second group ofterminal devices to at least cause the neighboring base stations tosuspend transmission on a carrier corresponding to the at least onesecondary cell.

In other embodiments, the method may further comprise allocating thereleased resources back to the first group of terminal devices if thesecond group of terminal devices leaves the coverage of the basestation.

In further embodiments, said obtaining information indicating arrival ofa second group of terminal devices may be achieved by detecting, at thebase station, the arrival of the second group of terminal devices orreceiving a message of the arrival of the second group of terminaldevices from a neighboring base station that obtains the informationindicating the arrival of the second group of terminal devices atcoverage of the neighboring base station.

In further embodiments, before receiving the message of the arrival ofthe second group of terminal devices from the neighboring base station,the method may further comprise triggering the neighboring base stationto report the arrival of the second group of terminal devices.

In further embodiments, said releasing resources on at least onesecondary cell may comprise any of the following: scheduling no resourceon the at least one secondary cell for the first group of terminaldevices; deactivating the at least one secondary cell for the firstgroup of terminal devices; and de-configuring the at least one secondarycell for the first group of terminal devices.

In further embodiments, said resources may comprise a frequencyresource.

In a second aspect of the present disclosure, a base station adapted forcoordinating resources in a wireless communications system with carrieraggregation is provided. In the wireless communications system, a firstgroup of terminal devices is served by a primary cell and one or moresecondary cells under control of the base station. The base stationcomprises an obtaining module that is configured to obtain informationindicating arrival of a second group of terminal devices at coverage ofthe base station. A speed of any terminal device of the second group ishigher than a speed of any terminal device of the first group. The basestation also comprises a releasing module that is configured to releaseresources on at least one secondary cell of the one or more secondarycells and an allocating module that is configured to allocate thereleased resources to the second group of terminal devices.

In some embodiments, the base station may further comprise an informingmodule that is configured to inform one or more neighboring basestations of the arrival of the second group of terminal devices to atleast cause the neighboring base stations to suspend transmission on acarrier corresponding to the at least one secondary cell.

In other embodiments, the allocating module may be further configured toallocate the released resources back to the first group of terminaldevices if the second group of terminal devices leaves the coverage ofthe base station.

In further embodiments, the obtaining module may be configured to obtainthe information indicating the arrival of the second group of terminaldevices by: detecting the arrival of the second group of terminaldevices; or receiving a message of the arrival of the second group ofterminal devices from a neighboring base station that obtains theinformation indicating the arrival of the second group of terminaldevices at coverage of the neighboring base station.

In further embodiments, the base station may further comprise atriggering module that is configured to trigger the neighboring basestation to report the arrival of the second group of terminal devices.

In further embodiments, the releasing module may be configured torelease the resources on the at least one secondary cell by any of thefollowing: scheduling no resource on the at least one secondary cell forthe first group of terminal devices, deactivating the at least onesecondary cell for the first group of terminal devices; andde-configuring the at least one secondary cell for the first group ofterminal devices.

In a third aspect of the present disclosure, a base station adapted forcoordinating resources in a wireless communications system with carrieraggregation is provided. In the wireless communications system, a firstgroup of terminal devices is served by a primary cell and one or moresecondary cells under control of the base station. The base stationcomprises a processor and a memory. The memory contains instructionsexecutable by said processor, whereby the base station is operative toobtain information indicating arrival of a second group of terminaldevices at coverage of the base station, wherein a speed of any terminaldevice of the second group is higher than a speed of any terminal deviceof the first group; release resources on at least one secondary cell ofthe one or more secondary cells; and allocate the released resources tothe second group of terminal devices.

In a fourth aspect of the present disclosure, a base station adapted forcoordinating resources in a wireless communications system with carrieraggregation is provided. In the wireless communications system, a firstgroup of terminal devices is served by a primary cell and one or moresecondary cells under control of the base station. The base stationcomprises processing means. The processing means is adapted to obtaininformation indicating arrival of a second group of terminal devices atcoverage of the base station. A speed of any terminal device of thesecond group is higher than a speed of any terminal device of the firstgroup. The processing means is also adapted to release resources on atleast one secondary cell of the one or more secondary cells and allocatethe released resources dedicated to the second group of terminaldevices.

In a fifth aspect of the present disclosure, a computer program isprovided. The computer program comprises instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the method according to the first aspect of the presentdisclosure.

It should be appreciated that, corresponding embodiments of the firstaspect are also applicable for the second aspect, the third aspect, thefourth aspect, and the fifth aspect.

With particular embodiments of the techniques described in thisspecification, by coordinating resources on secondary cells betweenlow-speed terminal devices and high-speed terminal devices in a wirelesscommunications system with carrier aggregation, QoS of the high-speedterminal devices may be guaranteed and the spectrum utilization may alsobe improved.

Other features and advantages of the embodiments of the presentdisclosure will also be understood from the following description ofspecific embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and benefits of variousembodiments of the disclosure will become more fully apparent, by way ofexample, from the following detailed description with reference to theaccompanying drawings, in which like reference numerals or letters areused to designate like or equivalent elements. The drawings areillustrated for facilitating better understanding of the embodiments ofthe disclosure and not necessarily drawn to scale, in which:

FIG. 1 illustrates two existing solutions for providing coverage forhigh speed train UEs in the prior art;

FIG. 2 illustrates an exemplary flowchart of a method for coordinatingresources in a wireless communications system with carrier aggregationaccording to an embodiment of the present disclosure;

FIG. 3 illustrates an example for signaling a message of arrival of ahigh-speed group via a single message procedure between two neighboringeNBs, according to an embodiment of the present disclosure;

FIG. 4 illustrates an exemplary signaling flow for indicating arrival ofa high-speed group of terminal devices based on a trigger-reportmechanism over the X2 interface;

FIG. 5 illustrates another exemplary signaling flow for indicatingarrival of the high-speed group of terminal devices based on thetrigger-report mechanism via an existing Request/Response procedure overthe X2 interface;

FIG. 6 explains advantages of the proposed method in an exemplarynetwork wherein each base station is configured with two carriers f1 andf2;

FIG. 7 illustrates a schematic block diagram of a base station that maybe configured to practice exemplary embodiments of the presentdisclosure; and

FIG. 8 illustrates a simplified block diagram of an apparatus that issuitable for use in practicing exemplary embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Hereinafter, the principle and spirit of the present disclosure will bedescribed with reference to the illustrative embodiments. It should beunderstood, all these embodiments are given merely for the skilled inthe art to better understand and further practice the presentdisclosure, but not for limiting the scope of the present disclosure.For example, features illustrated or described as part of one embodimentmay be used with another embodiment to yield still a further embodiment.In the interest of clarity, not all features of an actual implementationare described in this specification.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is within the knowledge of one skilled in the art toeffect such feature, structure, or characteristic in connection withother embodiments whether or not explicitly described.

It shall be understood that, although the terms ‘first’ and ‘second’etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first element couldbe termed a second element, and similarly, a second element could betermed a first element, without departing from the scope of exampleembodiments. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed terms.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be liming. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises”, “comprising”, “has”,“having”, “includes” and/or “including”, when used herein, specify thepresence of stated features, elements, and/or components etc., but donot preclude the presence or addition of one or more other features,elements, components and/or combinations thereof.

In the following description and claims, unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art to which thisdisclosure belongs. For example, the term “base station” (BS), usedherein may be referred to as e.g. eNB, eNodeB, NodeB or base transceiverstation (BTS) etc. depending on the technology and terminology used,which may configure de-configure and activate/de-activate secondarycells and schedule resources on the secondary cells, for example.Likewise, the term “terminal device” or UE used herein may refer to anyterminal having wireless communication capabilities, including but notlimited to, mobile phones, cellular phones, smart phones, or personaldigital assistants (PDAs), portable computers, image capture devicessuch as digital cameras, gaming devices, music storage and playbackappliances and any portable units or terminals that have wirelesscommunication capabilities, or Internet appliances permitting wirelessInternet access and browsing and the like. In the following description,the terms “user equipment” or “UE” and “terminal device” may be usedinterchangeably and the terms “base station” or “BS” and “eNodeB” or“eNB” may be used interchangeably hereinafter.

For illustrative purposes, several embodiments of the present disclosurewill be described in the HST scenario. Those skilled in the art willappreciate, however, that several embodiments of the present disclosuremay be more generally applicable to other high-speed UE involvedscenarios. It should also be appreciated that, the terms “high speed”and “low speed” used herein are relative. In different environments,different speeds may be considered a high speed or low speed. Briefly, aspeed higher than a first threshold may be considered a high speed, anda speed lower than a second threshold may be considered a low speed. Thefirst and second thresholds may be the same or different. For example,in the HST scenario, the speed more than 250 km/h may be considered as ahigh speed and the speed lower than 160 km/h may be considered as a lowspeed. Obviously, the scope of the present disclosure is not limited howthe terms “high speed” and “low speed” are defined.

While embodiments of the present disclosure are described herein in thecontext of a LTE network with carrier aggregation for illustrativepurposes, those skilled in the art shall appreciate that the embodimentsdisclosed herein may also be applied to various other types of networksusing more than one carrier.

FIG. 2 illustrates an exemplary flowchart of a method 200 forcoordinating resources in a wireless communications system with carrieraggregation according to an embodiment of the present disclosure. Themethod is implemented in a base station of the wireless communicationssystem, in which a first group of terminal devices is served by aprimary cell and one or more secondary cells that are under control ofthe base station.

As illustrated in FIG. 2, at block S210, information indicating arrivalof a second group of terminal devices at coverage of the base station isobtained. A speed of any terminal device of the second group is higherthan a speed of any terminal device of the first group. The first groupmay be referred to as a low-speed group and the terminal devicescomprised therein may be referred to as low-speed terminal devices.Likewise, the second group may be referred to as a high-speed group andthe terminal devices comprised therein may be referred to as high-speedterminal devices. The coverage of the base station may physically atleast comprise the primary cell and the one or more secondary cells.

In one embodiment, the base station may obtain the informationindicating the arrival of the second group of terminal devices bylocally detecting the arrival of the high-speed terminal devices. Forexample, Reference 1 with international application NO.PCT/CN2013/087917 discloses a method for detecting high-speed terminaldevices, which is already known to those skilled in the art and thuswill not be detailed herein for the sake of conciseness.

In another embodiment, it is possible for the base station to obtaininformation on the arrival of the high-speed group from a neighboringbase station that has already obtained the information indicating thearrival of the second group of terminal devices at its own coverage.Especially for the HST scenario, due to the continuous character of arail track, the HST may move from a cell to a neighboring cellsequentially along the rail track. Therefore, such information may besignaled in a sequential way among the base stations deployed along therail track.

FIG. 3 illustrates an example for signaling the message of the arrivalof the high-speed group via a single message procedure between twoneighboring eNBs, according to an embodiment of the present disclosure.In this example, assuming that the train will pass eNB1 first (which maybe referred to as a “upstream eNB”) and subsequently pass eNB2 (whichmay be referred to as a “downstream eNB”), then eNB1 that may havelocally detected the arrival of the high-speed group of terminal devicesor have obtained the information on the arrival from its own upstreamneighboring eNB may notify eNB2 that the high-speed group of terminaldevices arrives at the coverage of eNB1 via high layer signaling, e.g.RRC signaling, over an inter-node interface, such as the X2 interface.The RRC signaling may be existing or new, e.g. RRCHighSpeedNotificationas illustrated in FIG. 3. This signaling may function prior to ahandover procedure or it may be embedded in the signaling for thehandover procedure. Additionally, once the downstream eNB2 receives thenotification and accordingly performs operations as described later,e.g. secondary cell releasing, it may notify back to the upstream eNB1that corresponding operations are completed, e.g. via aRRCHighSpeedComplete message as illustrated.

In another embodiment, before the information indicating the high speedgroup arrival is received by the base station, it may trigger at blockS205 its neighboring base station that is located upstream and may haveobtained information indicating the high speed group arrival at its owncoverage to report the high speed group arrival. This mechanism may becalled a trigger-report mechanism. An advantage to enable such amechanism is to provide a control over the level of signalingindications and manage signaling overhead. Another advantage is to havea control of the signaling frequency, which may be for example periodicwith a selected period or simply event triggered, i.e. a-periodic, e.g.when approaching of a high speed train is detected. Additionally, thetrigger-report mechanism may be easily adapted to manage situations ofcell overload, which may be realized by further signaling a messagerequesting a stop of the high speed group arrival report. A cause valueor an equivalent information element (IE) value may indicate a reasonfor the request of the stop, which may be caused by a high cell load,for example.

FIG. 4 illustrates an exemplary signaling flow for indicating thearrival of the high-speed group of terminal devices based on thetrigger-report mechanism over the X2 interface. As illustrated, thedownstream eNB2 firstly signals to trigger the upstream eNB1 to reportthe high speed group arrival. Then the upstream eNB1 replies toacknowledge the reporting of the high speed group arrival. Subsequently,the upstream eNB1 may report the high speed group arrival to thedownstream eNB2 when it actually happens.

FIG. 5 illustrates another exemplary signaling flow for indicating thearrival of the second group of terminal devices based on thetrigger-report mechanism via an existing Request/Response procedure overthe X2 interface. The existing procedures that may be reused for such anindication may be an X2 Load Indication or Resource StatusRequest/Response/Update messages. As illustrated, the downstream eNB2may firstly trigger periodic or aperiodic reporting of the high-speedgroup arrival via a Resource Status Request message over the X2interface, and subsequently the upstream eNB1 may acknowledge thereporting of the high-speed group arrival in a Resource Status Responsemessage. Subsequently, eNB1 may indicate the high-speed group arrival ina Resource Status Update message when the high-speed group actuallyarrives. Once the downstream eNB2 receives this indication, it willcarry out operations as described in relation to blocks 220-240 in thefollowing. Afterwards, the downstream eNB2 may additionally andpreferably request the upstream eNB1 to stop reporting the high-speedgroup arrival in a Resource Status Request message and likewise, theupstream eNB1 may acknowledge the stop of reporting of the high-speedgroup arrival in a Resource Status Response message. Usually, thesignaling for the stop of reporting happens in a case that the reportingis event triggered.

Now, the flow of method 200 may proceed to block S220. In response toreceiving the information indicating the arrival of the second (i.e.high-speed) group of terminal devices at the coverage of the basestation, resources on at least one secondary cell of the one or moresecondary cells are released at block S220 by the base station.

As mentioned in the Background, before a terminal device supportingcarrier aggregation can use Scells, it shall be firstly configured withthe Scells, and the configured Scells shall be activated and then may bescheduled for use. Accordingly, reverse operations to the configuration,activation and scheduling may constitute three different approaches forreleasing the resources on the SCells.

For example, the resources on the SCells may be released by notscheduling any resource on the SCells for the low-speed group ofterminal devices. Since this approach may be implemented on the physicallayer without involving high layer signaling, it may complete resourcereleasing very fast, usually within 1 millisecond (ms).

For another example, the resources on the Scells may be released bydeactivating the Scells for the low-speed group of terminal devices. Asintroduced in the Background, the deactivation may be implemented by aMAC control element. For example, the MAC control element may carry abitmap for the deactivation of Scells in which a bit set to 1 denotesactivation of the corresponding Scell while a bit set to 0 denotesdeactivation. With the bitmap, Scells can be activated and deactivatedindividually, and a single activation/deactivation command canactivate/deactivate a subset of the SCells. The deactivation approachusually takes a time in an order of 10 ms for resource releasing.

For yet another example, the resources on the SCells may be released byde-configuring the SCells for the low-speed group of terminal devices.The do-configuration may be performed through existing RRC signaling,e.g. RRCConnectionReconfiguration. The de-configuration approach usuallytakes a time in an order of 100 ms for resource releasing.

Now, the flow of method 200 proceeds to block S230. Once the resourceson the at least one SCell are released, the released resources areallocated to the second group of terminal devices at block S230. Inparticular, these released resources are dedicatedly used for the secondgroup of terminal devices. The allocating operation may compriseconfiguring the at least SCell for the second group of terminal devicesand activating them and then scheduling the resources on the at leastSCell for transmission of the second group of terminal devices. Theallocating operation is well known in the art, the description of whichthus will be omitted herein for the sake of conciseness.

Preferably, in order to avoid or alleviate intra-frequency interferencefrom neighboring cells, the base station may inform at block S240 one ormore of its neighboring base station s of the arrival of the secondgroup of terminal devices so that the one or more neighboring basestations may suspend transmission on a carrier corresponding to the atleast one secondary cell in their own coverage.

Additionally, if the high-speed group of terminal devices leaves thecoverage of the base station, the base station may allocate the releasedresources back to the low-speed group of terminal devices at block S250of method 200 as illustrated in FIG. 2.

According to the above embodiments of the present disclosure, there isproposed a dynamic, fast, cost-and-spectrum efficient method to secureQoS via good interference management between high-speed and low-speedterminal devices.

The benefits and advantages of the proposed method 200 will be visuallyexplained in an exemplary network wherein each base station isconfigured with two carriers f1 and f2 as illustrated in FIG. 6. In thisexample, it is assumed that carrier f1 is configured as the PCell andcarrier 12 is configured as the SCell. Those skilled in the art shallappreciate that more carriers may be used in practical applications.

As illustrated in FIG. 6, both carriers may serve low-speed terminaldevices when no HST arrives at the coverage of base station BS1. Alllow-speed terminal devices are registered in the PCell. Upon the HSTarrives, carrier f2 as the SCell will be “released” for dedicate use byhigh-speed terminal devices on the HST. Therefore, service switchingbetween low-speed terminal devices and high-speed devices is totallydepending on the arrival of the HST and thus may be implementeddynamically. Furthermore, the speed for the SCell releasing is very fastas discussed above. Thus the service switching may be realized in realtime.

Unlike dedicated solution in FIG. 1(b), both carriers f1 and f2 asillustrated in FIG. 6 may be flexibly allocated for low-speed orhigh-speed terminal devices by appropriately using signaling over the X2interface, for example. Therefore, such a method 200 needs no additionalinvestment on separate sites/antennas while achieving high spectrumutilization.

Furthermore, when the HST arrives at the coverage of BS1 as illustratedin FIG. 6, transmissions on carrier f2 of neighboring base stations,e.g. BS2 are all suspended. Therefore, intra-frequency interference fromneighboring cells is under a good control. Accordingly, QoS for thehigh-speed terminal devices on the HST is ensured.

FIG. 7 illustrates a schematic block diagram of a base station 700 thatmay be configured to practice the exemplary embodiments herein. The basestation 700 is adapted to coordinate resources in a wirelesscommunications system with carrier aggregation in which a first group ofterminal devices is served by a primary cell and one or more secondarycells under the control of the base station 700.

As illustrated in FIG. 7, the base station 700 comprises an obtainingmodule 710, a releasing module 720, and an allocating module 730.

The obtaining module 710 is configured to obtain information indicatingarrival of a second group of terminal devices at coverage of the basestation 700. A speed of any terminal device of the second group ishigher than a speed of any terminal device of the first group and thecoverage may at least comprise the primary cell and the one or moresecondary cells.

In some embodiments, the obtaining module 710 may be configured toobtain the information indicating the arrival of the second group ofterminal devices by locally detecting the arrival of the second group ofterminal devices or receiving a message of the arrival of the secondgroup of terminal devices from a neighboring base station that obtainsthe information indicating the arrival of the second group of terminaldevices at coverage of the neighboring base station. The operations ofthe obtaining module 710 correspond to those described above in relationto block S210 of FIG. 2 and thus the detailed description thereof willbe omitted herein for the sake of conciseness.

The releasing module 720 is configured to release resources on at leastone secondary cell of the one or more secondary cells.

In some embodiment, the releasing module 720 may be configured torelease the resources on the at least one secondary cell by schedulingno resource on the at least one secondary cell for the first group ofterminal devices, deactivating the at least one secondary cell for thefirst group of terminal devices, and de-configuring the at least onesecondary cell for the first group of terminal devices. The operationsof the releasing module 720 correspond to those described above inrelation to block 8220 of FIG. 2 and thus the detailed descriptionthereof will be omitted herein for the sake of conciseness.

The allocating module 730 is configured to allocate the releasedresources to the second group of terminal devices.

In some embodiments, the allocating module 730 may be further configuredto allocate the released resources back to the first group of terminaldevices if the second group of terminal devices leaves the coverage ofthe base station 700.

As illustrated in FIG. 7, the base station 700 may further comprise aninforming module 740. The informing module 740 may be configured toinform one or more neighboring base stations of the arrival of thesecond group of terminal devices to at least cause the neighboring basestations to suspend transmission on a carrier corresponding to the atleast one secondary cell. The operations of the releasing module 720correspond to those described above in relation to block S240 of FIG. 2and thus the detailed description thereof will be omitted herein for thesake of conciseness.

As illustrated in FIG. 7, the base station 700 may further comprise atriggering module 750. The triggering module 750 may be configured totrigger the neighboring base station to report the arrival of the secondgroup of terminal devices. The operations of the releasing module 720correspond to those described above in relation to block S205 of FIG. 2and thus the detailed description thereof will be omitted herein for thesake of conciseness.

FIG. 8 illustrates a simplified block diagram of an apparatus 800 thatis suitable for use in practicing exemplary embodiments of the presentdisclosure. The apparatus 800 may be embodied in or as a base station.

As shown in FIG. 8, the apparatus 800 includes a data processor (DP)810, a memory (MEM) 820 coupled to the DP 810, a suitable RF transmitterTX and receiver RX 840 coupled to the DP 810, and a communicationinterface 850 coupled to the DP 810. The MEM 820 stores a program (PROG)830. The TX/RX 840 is for bidirectional wireless communications. Notethat the TX/RX 840 has at least one antenna to facilitate communication,though in practice a BS may have several ones. The communicationinterface 850 may represent any interface that is necessary forcommunication with other network elements, such as X2 interface forbidirectional communications between eNBs, S1 interface forcommunication between a Mobility Management Entity (MME)/Serving Gateway(S-GW) and the eNB, or Un interface for communication between the eNBand a relay node (RN). The apparatus 800 may be coupled via a data pathto one or more external networks or systems, such as the internet, forexample.

The PROG 830 is assumed to include program instructions that, whenexecuted by the associated DP 810, enable the apparatus 800 to operatein accordance with the exemplary embodiments of this disclosure, asdiscussed herein with the method in FIG. 2. For example, the PROG 830and the DP 810 may embody the releasing module 720 and the allocatingmodule 730 to perform the respective operations. The TX/RX 840 and thecommunication interface 850 may embody the obtaining module 710 andoptional the informing module 740 and the triggering module 750 toperform the respective operations.

The embodiments herein may be implemented by computer softwareexecutable by the DP 810 of the apparatus 800, or by hardware, or by acombination of software and hardware.

A combination of the data processor 810 and MEM 820 may form processingmeans 860 adapted to implement various embodiments of the presentdisclosure.

The MEM 820 may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor based memory devices, magnetic memorydevices and systems, optical memory devices and systems, fixed memoryand removable memory, as non-limiting examples. While only one MEM isshown in the apparatus 800, there may be several physically distinctmemory units in the apparatus 800. The DP 810 may be of any typesuitable to the local technical environment, and may include one or moreof general purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs) and processors basedon multicore processor architecture, as non limiting examples. Theapparatus 800 may have multiple processors, such as for example anapplication specific integrated circuit chip that is slaved in time to aclock which synchronizes the main processor.

Exemplary embodiments herein have been described above with reference toblock diagrams and flowchart illustrations of methods, apparatuses(i.e., systems). It will be understood that each block of the blockdiagrams and flowchart illustrations, and combinations of blocks in theblock diagrams and flowchart illustrations, respectively, can beimplemented by various means including computer program instructions.These computer program instructions may be loaded onto a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructionswhich execute on the computer or other programmable data processingapparatus create processing means for implementing the functionsspecified in the flowchart block or blocks.

The foregoing computer program instructions can be, for example,sub-routines and/or functions. A computer program product in oneembodiment comprises at least one computer readable storage medium, onwhich the foregoing computer program instructions are stored. Thecomputer readable storage medium can be, for example, an optical compactdisk or an electronic memory device like a RAM (random access memory) ora ROM (read only memory).

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyimplementation or of what may be claimed, but rather as descriptions offeatures that may be specific to particular embodiments of particularimplementations. Certain features that are described in thisspecification in the context of separate embodiments may also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment mayalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or variation of a sub-combination.

It should also be appreciated that the above described embodiments aregiven for describing rather than limiting the disclosure, and it is tobe understood that modifications and variations may be resorted towithout departing from the spirit and scope of the disclosure as thoseskilled in the art readily understand. Such modifications and variationsare considered to be within the scope of the disclosure and the appendedclaims. The protection scope of the disclosure is defined by theaccompanying claims. In addition, any of the reference numerals in theclaims should not be interpreted as a limitation to the claims. Use ofthe verb “comprise” and its conjugations does not exclude the presenceof elements or steps other than those stated in a claim. The indefinitearticle “a” or “an” preceding an element or step does not exclude thepresence of a plurality of such elements or steps.

What is claimed is:
 1. A method in a base station for coordinatingresources in a wireless communications system with carrier aggregation,the method comprising: serving, by the base station, a first group ofterminal devices using at least one resource associated with a primarycell and at least one resource associated with a secondary cell;obtaining information indicating arrival of a second group of terminaldevices at coverage of the base station; determining that a speed of atleast one terminal device of the second group of terminal devices ishigher than a speed of at least one terminal device of the first groupof the terminal devices; in response to determining that the speed ofthe at least one terminal device of the second group of terminal devicesis higher than the speed of the at least one terminal device of thefirst group of terminal devices, releasing resources on at least onesecondary cell of the one or more secondary cells; and allocating thereleased resources on the at least one secondary cell to the secondgroup of terminal devices by configuring the at least one secondary cellof the one or more secondary cells for the second group of terminaldevices.
 2. The method according to claim 1, further comprising:informing one or more neighboring base stations of the arrival of thesecond group of terminal devices to at least cause the neighboring basestations to suspend transmission on a carrier corresponding to the atleast one secondary cell.
 3. The method according to claim 1, furthercomprising: allocating the released resources back to the first group ofterminal devices if the second group of terminal devices leaves thecoverage of the base station.
 4. The method according to claim 1, saidreleasing resources on at least one secondary cell comprising any of thefollowing: scheduling no resource on the at least one secondary cell forthe first group of terminal devices; deactivating the at least onesecondary cell for the first group of terminal devices; andde-configuring the at least one secondary cell for the first group ofterminal devices.
 5. The method according to claim 1, wherein saidresources comprise frequency resource.
 6. A base station adapted forcoordinating resources in a wireless communications system with carrieraggregation in which a first group of terminal devices is served by aprimary cell and one or more secondary cells under control of the basestation, the base station comprising: a processor; and a memory, saidmemory containing instructions executable by said processor, wherebysaid base station is operative to: serve a first group of terminaldevices using at least one resource associated with a primary cell andat least one resource associated with a secondary cell; obtaininformation indicating arrival of a second group of terminal devices atcoverage of the base station; determining that a speed of at least oneterminal device of the second group of terminal devices is higher than aspeed of at least one terminal device of the first group of terminaldevices; in response to determining that the speed of the at least oneterminal device of the second group of terminal devices is higher thanthe speed of the at least one terminal device of the first group ofterminal devices, release resources on at least one secondary cell ofthe one or more secondary cells; and allocate the released resources onthe at least one secondary cell to the second group of terminal devicesby configuring the at least one secondary cell of the one or moresecondary cells for the second group of terminal devices.
 7. The basestation according to claim 6, wherein the base station is furtheroperative to: inform one or more neighboring base stations of thearrival of the second group of terminal devices to at least cause theneighboring base stations to suspend transmission on a carriercorresponding to the at least one secondary cell.
 8. The base stationaccording to claim 6, wherein the base station is further operative to:allocate the released resources back to the first group of terminaldevices if the second group of terminal devices leaves the coverage ofthe base station.
 9. The base station according to claim 6, wherein thebase station is operative to release resources on at least one secondarycell by any of the following: scheduling no resource on the at least onesecondary cell for the first group of terminal devices; deactivating theat least one secondary cell for the first group of terminal devices; andde-configuring the at least one secondary cell for the first group ofterminal devices.
 10. The base station according to claim 6, whereinsaid resources comprise frequency resource.
 11. A base station adaptedfor coordinating resources in a wireless communications system withcarrier aggregation in which a first group of terminal devices is servedby a primary cell and one or more secondary cells under control of thebase station, the base station comprising processing means adapted to:serve a first group of terminal devices using at least one resourceassociated with a primary cell and at least one resource associated witha secondary cell; obtain information indicating arrival of a secondgroup of terminal devices at coverage of the base station; determinethat a speed of at least one terminal device of the second group ofterminal devices is higher than a speed of at least one terminal deviceof the first group of terminal devices; in response to determining thatthe speed of the at least one terminal device of the second group ofterminal devices is higher than the speed of the at least one terminaldevice of the first group of terminal devices, release resources on atleast one secondary cell of the one or more secondary cells; andallocate the released resources on the at least one secondary cell tothe second group of terminal devices by configuring the at least onesecondary cell of the one or more secondary cells for the second groupof terminal devices.
 12. The base station according to claim 11, whereinthe processing means is further adapted to: inform one or moreneighboring base stations of the arrival of the second group of terminaldevices to at least cause the neighboring base stations to suspendtransmission on a carrier corresponding to the at least one secondarycell.
 13. The base station according to claim 11, wherein the processingmeans is further adapted to: allocate the released resources back to thefirst group of terminal devices if the second group of terminal devicesleaves the coverage of the base station.